Scientists have found vast frozen plains next door to Pluto's big, rugged mountains of water ice.
The New Horizons spacecraft team revealed close-up photos of those plains on Friday, three days after the historic flyby.
Scientists have unofficially named the plains after Sputnik, the world's first man-made satellite.
Spanning a couple hundred miles, the plains are located in the bright, heart-shaped area of Pluto.
Like the mountains unveiled on Wednesday, the plains look to be a relatively young 100 million years old.
Scientists speculate internal heating - perhaps from volcanoes or geysers - might be responsible for these youthful-looking, crater-free regions.
The plains appear to include smooth hills and fields of small pits.
Principal scientist Alan Stern says the pictures coming from 3 billion miles (5 billion kms) away are "beautiful eye candy."
